unittests/Tooling/RecursiveASTVisitorTest.cpp

//===- unittest/Tooling/RecursiveASTVisitorTest.cpp -----------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "TestVisitor.h"

#include <stack>

namespace clang {

class TypeLocVisitor : public ExpectedLocationVisitor<TypeLocVisitor> {
public:
  bool VisitTypeLoc(TypeLoc TypeLocation) {
    Match(TypeLocation.getType().getAsString(), TypeLocation.getBeginLoc());
    return true;
  }
};

class DeclRefExprVisitor : public ExpectedLocationVisitor<DeclRefExprVisitor> {
public:
  bool VisitDeclRefExpr(DeclRefExpr *Reference) {
    Match(Reference->getNameInfo().getAsString(), Reference->getLocation());
    return true;
  }
};

class VarDeclVisitor : public ExpectedLocationVisitor<VarDeclVisitor> {
public:
 bool VisitVarDecl(VarDecl *Variable) {
   Match(Variable->getNameAsString(), Variable->getLocStart());
   return true;
 }
};

class ParmVarDeclVisitorForImplicitCode :
  public ExpectedLocationVisitor<ParmVarDeclVisitorForImplicitCode> {
public:
  bool shouldVisitImplicitCode() const { return true; }

  bool VisitParmVarDecl(ParmVarDecl *ParamVar) {
    Match(ParamVar->getNameAsString(), ParamVar->getLocStart());
    return true;
  }
};

class CXXMemberCallVisitor
  : public ExpectedLocationVisitor<CXXMemberCallVisitor> {
public:
  bool VisitCXXMemberCallExpr(CXXMemberCallExpr *Call) {
    Match(Call->getMethodDecl()->getQualifiedNameAsString(),
          Call->getLocStart());
    return true;
  }
};

class NamedDeclVisitor
  : public ExpectedLocationVisitor<NamedDeclVisitor> {
public:
  bool VisitNamedDecl(NamedDecl *Decl) {
    std::string NameWithTemplateArgs;
    llvm::raw_string_ostream OS(NameWithTemplateArgs);
    Decl->getNameForDiagnostic(OS,
                               Decl->getASTContext().getPrintingPolicy(),
                               true);
    Match(OS.str(), Decl->getLocation());
    return true;
  }
};

class CXXOperatorCallExprTraverser
  : public ExpectedLocationVisitor<CXXOperatorCallExprTraverser> {
public:
  // Use Traverse, not Visit, to check that data recursion optimization isn't
  // bypassing the call of this function.
  bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr *CE) {
    Match(getOperatorSpelling(CE->getOperator()), CE->getExprLoc());
    return ExpectedLocationVisitor<CXXOperatorCallExprTraverser>::
        TraverseCXXOperatorCallExpr(CE);
  }
};

class ParenExprVisitor : public ExpectedLocationVisitor<ParenExprVisitor> {
public:
  bool VisitParenExpr(ParenExpr *Parens) {
    Match("", Parens->getExprLoc());
    return true;
  }
};

class LambdaExprVisitor : public ExpectedLocationVisitor<LambdaExprVisitor> {
public:
  bool VisitLambdaExpr(LambdaExpr *Lambda) {
    PendingBodies.push(Lambda);
    Match("", Lambda->getIntroducerRange().getBegin());
    return true;
  }
  /// For each call to VisitLambdaExpr, we expect a subsequent call (with
  /// proper nesting) to TraverseLambdaBody.
  bool TraverseLambdaBody(LambdaExpr *Lambda) {
    EXPECT_FALSE(PendingBodies.empty());
    EXPECT_EQ(PendingBodies.top(), Lambda);
    PendingBodies.pop();
    return TraverseStmt(Lambda->getBody());
  }
  /// Determine whether TraverseLambdaBody has been called for every call to
  /// VisitLambdaExpr.
  bool allBodiesHaveBeenTraversed() const {
    return PendingBodies.empty();
  }
private:
  std::stack<LambdaExpr *> PendingBodies;
};

// Matches the (optional) capture-default of a lambda-introducer.
class LambdaDefaultCaptureVisitor
  : public ExpectedLocationVisitor<LambdaDefaultCaptureVisitor> {
public:
  bool VisitLambdaExpr(LambdaExpr *Lambda) {
    if (Lambda->getCaptureDefault() != LCD_None) {
      Match("", Lambda->getCaptureDefaultLoc());
    }
    return true;
  }
};

class TemplateArgumentLocTraverser
  : public ExpectedLocationVisitor<TemplateArgumentLocTraverser> {
public:
  bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
    std::string ArgStr;
    llvm::raw_string_ostream Stream(ArgStr);
    const TemplateArgument &Arg = ArgLoc.getArgument();

    Arg.print(Context->getPrintingPolicy(), Stream);
    Match(Stream.str(), ArgLoc.getLocation());
    return ExpectedLocationVisitor<TemplateArgumentLocTraverser>::
      TraverseTemplateArgumentLoc(ArgLoc);
  }
};

class CXXBoolLiteralExprVisitor 
  : public ExpectedLocationVisitor<CXXBoolLiteralExprVisitor> {
public:
  bool VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *BE) {
    if (BE->getValue())
      Match("true", BE->getLocation());
    else
      Match("false", BE->getLocation());
    return true;
  }
};

// Test RAV visits parameter variable declaration of the implicit
// copy assignment operator and implicit copy constructor.
TEST(RecursiveASTVisitor, VisitsParmVarDeclForImplicitCode) {
  ParmVarDeclVisitorForImplicitCode Visitor;
  // Match parameter variable name of implicit copy assignment operator and
  // implicit copy constructor.
  // This parameter name does not have a valid IdentifierInfo, and shares
  // same SourceLocation with its class declaration, so we match an empty name
  // with the class' source location.
  Visitor.ExpectMatch("", 1, 7);
  Visitor.ExpectMatch("", 3, 7);
  EXPECT_TRUE(Visitor.runOver(
    "class X {};\n"
    "void foo(X a, X b) {a = b;}\n"
    "class Y {};\n"
    "void bar(Y a) {Y b = a;}"));
}

TEST(RecursiveASTVisitor, VisitsBaseClassDeclarations) {
  TypeLocVisitor Visitor;
  Visitor.ExpectMatch("class X", 1, 30);
  EXPECT_TRUE(Visitor.runOver("class X {}; class Y : public X {};"));
}

TEST(RecursiveASTVisitor, VisitsCXXBaseSpecifiersOfForwardDeclaredClass) {
  TypeLocVisitor Visitor;
  Visitor.ExpectMatch("class X", 3, 18);
  EXPECT_TRUE(Visitor.runOver(
    "class Y;\n"
    "class X {};\n"
    "class Y : public X {};"));
}

TEST(RecursiveASTVisitor, VisitsCXXBaseSpecifiersWithIncompleteInnerClass) {
  TypeLocVisitor Visitor;
  Visitor.ExpectMatch("class X", 2, 18);
  EXPECT_TRUE(Visitor.runOver(
    "class X {};\n"
    "class Y : public X { class Z; };"));
}

TEST(RecursiveASTVisitor, VisitsCXXBaseSpecifiersOfSelfReferentialType) {
  TypeLocVisitor Visitor;
  Visitor.ExpectMatch("X<class Y>", 2, 18);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename T> class X {};\n"
    "class Y : public X<Y> {};"));
}

TEST(RecursiveASTVisitor, VisitsBaseClassTemplateArguments) {
  DeclRefExprVisitor Visitor;
  Visitor.ExpectMatch("x", 2, 3);
  EXPECT_TRUE(Visitor.runOver(
    "void x(); template <void (*T)()> class X {};\nX<x> y;"));
}

TEST(RecursiveASTVisitor, VisitsCXXForRangeStmtRange) {
  DeclRefExprVisitor Visitor;
  Visitor.ExpectMatch("x", 2, 25);
  Visitor.ExpectMatch("x", 2, 30);
  EXPECT_TRUE(Visitor.runOver(
    "int x[5];\n"
    "void f() { for (int i : x) { x[0] = 1; } }",
    DeclRefExprVisitor::Lang_CXX11));
}

TEST(RecursiveASTVisitor, VisitsCXXForRangeStmtLoopVariable) {
  VarDeclVisitor Visitor;
  Visitor.ExpectMatch("i", 2, 17);
  EXPECT_TRUE(Visitor.runOver(
    "int x[5];\n"
    "void f() { for (int i : x) {} }",
    VarDeclVisitor::Lang_CXX11));
}

TEST(RecursiveASTVisitor, VisitsCallExpr) {
  DeclRefExprVisitor Visitor;
  Visitor.ExpectMatch("x", 1, 22);
  EXPECT_TRUE(Visitor.runOver(
    "void x(); void y() { x(); }"));
}

TEST(RecursiveASTVisitor, VisitsCallInTemplateInstantiation) {
  CXXMemberCallVisitor Visitor;
  Visitor.ExpectMatch("Y::x", 3, 3);
  EXPECT_TRUE(Visitor.runOver(
    "struct Y { void x(); };\n"
    "template<typename T> void y(T t) {\n"
    "  t.x();\n"
    "}\n"
    "void foo() { y<Y>(Y()); }"));
}

TEST(RecursiveASTVisitor, VisitsCallInNestedFunctionTemplateInstantiation) {
  CXXMemberCallVisitor Visitor;
  Visitor.ExpectMatch("Y::x", 4, 5);
  EXPECT_TRUE(Visitor.runOver(
    "struct Y { void x(); };\n"
    "template<typename T> struct Z {\n"
    "  template<typename U> static void f() {\n"
    "    T().x();\n"
    "  }\n"
    "};\n"
    "void foo() { Z<Y>::f<int>(); }"));
}

TEST(RecursiveASTVisitor, VisitsCallInNestedClassTemplateInstantiation) {
  CXXMemberCallVisitor Visitor;
  Visitor.ExpectMatch("A::x", 5, 7);
  EXPECT_TRUE(Visitor.runOver(
    "template <typename T1> struct X {\n"
    "  template <typename T2> struct Y {\n"
    "    void f() {\n"
    "      T2 y;\n"
    "      y.x();\n"
    "    }\n"
    "  };\n"
    "};\n"
    "struct A { void x(); };\n"
    "int main() {\n"
    "  (new X<A>::Y<A>())->f();\n"
    "}"));
}

/* FIXME: According to Richard Smith this is a bug in the AST.
TEST(RecursiveASTVisitor, VisitsBaseClassTemplateArgumentsInInstantiation) {
  DeclRefExprVisitor Visitor;
  Visitor.ExpectMatch("x", 3, 43);
  EXPECT_TRUE(Visitor.runOver(
    "template <typename T> void x();\n"
    "template <void (*T)()> class X {};\n"
    "template <typename T> class Y : public X< x<T> > {};\n"
    "Y<int> y;"));
}
*/

TEST(RecursiveASTVisitor, VisitsCallInPartialTemplateSpecialization) {
  CXXMemberCallVisitor Visitor;
  Visitor.ExpectMatch("A::x", 6, 20);
  EXPECT_TRUE(Visitor.runOver(
    "template <typename T1> struct X {\n"
    "  template <typename T2, bool B> struct Y { void g(); };\n"
    "};\n"
    "template <typename T1> template <typename T2>\n"
    "struct X<T1>::Y<T2, true> {\n"
    "  void f() { T2 y; y.x(); }\n"
    "};\n"
    "struct A { void x(); };\n"
    "int main() {\n"
    "  (new X<A>::Y<A, true>())->f();\n"
    "}\n"));
}

TEST(RecursiveASTVisitor, VisitsExplicitTemplateSpecialization) {
  CXXMemberCallVisitor Visitor;
  Visitor.ExpectMatch("A::f", 4, 5);
  EXPECT_TRUE(Visitor.runOver(
    "struct A {\n"
    "  void f() const {}\n"
    "  template<class T> void g(const T& t) const {\n"
    "    t.f();\n"
    "  }\n"
    "};\n"
    "template void A::g(const A& a) const;\n"));
}

TEST(RecursiveASTVisitor, VisitsPartialTemplateSpecialization) {
  // From cfe-commits/Week-of-Mon-20100830/033998.html
  // Contrary to the approach suggested in that email, we visit all
  // specializations when we visit the primary template.  Visiting them when we
  // visit the associated specialization is problematic for specializations of
  // template members of class templates.
  NamedDeclVisitor Visitor;
  Visitor.ExpectMatch("A<bool>", 1, 26);
  Visitor.ExpectMatch("A<char *>", 2, 26);
  EXPECT_TRUE(Visitor.runOver(
    "template <class T> class A {};\n"
    "template <class T> class A<T*> {};\n"
    "A<bool> ab;\n"
    "A<char*> acp;\n"));
}

TEST(RecursiveASTVisitor, VisitsUndefinedClassTemplateSpecialization) {
  NamedDeclVisitor Visitor;
  Visitor.ExpectMatch("A<int>", 1, 29);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename T> struct A;\n"
    "A<int> *p;\n"));
}

TEST(RecursiveASTVisitor, VisitsNestedUndefinedClassTemplateSpecialization) {
  NamedDeclVisitor Visitor;
  Visitor.ExpectMatch("A<int>::B<char>", 2, 31);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename T> struct A {\n"
    "  template<typename U> struct B;\n"
    "};\n"
    "A<int>::B<char> *p;\n"));
}

TEST(RecursiveASTVisitor, VisitsUndefinedFunctionTemplateSpecialization) {
  NamedDeclVisitor Visitor;
  Visitor.ExpectMatch("A<int>", 1, 26);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename T> int A();\n"
    "int k = A<int>();\n"));
}

TEST(RecursiveASTVisitor, VisitsNestedUndefinedFunctionTemplateSpecialization) {
  NamedDeclVisitor Visitor;
  Visitor.ExpectMatch("A<int>::B<char>", 2, 35);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename T> struct A {\n"
    "  template<typename U> static int B();\n"
    "};\n"
    "int k = A<int>::B<char>();\n"));
}

TEST(RecursiveASTVisitor, NoRecursionInSelfFriend) {
  // From cfe-commits/Week-of-Mon-20100830/033977.html
  NamedDeclVisitor Visitor;
  Visitor.ExpectMatch("vector_iterator<int>", 2, 7);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename Container>\n"
    "class vector_iterator {\n"
    "    template <typename C> friend class vector_iterator;\n"
    "};\n"
    "vector_iterator<int> it_int;\n"));
}

TEST(RecursiveASTVisitor, TraversesOverloadedOperator) {
  CXXOperatorCallExprTraverser Visitor;
  Visitor.ExpectMatch("()", 4, 9);
  EXPECT_TRUE(Visitor.runOver(
    "struct A {\n"
    "  int operator()();\n"
    "} a;\n"
    "int k = a();\n"));
}

TEST(RecursiveASTVisitor, VisitsParensDuringDataRecursion) {
  ParenExprVisitor Visitor;
  Visitor.ExpectMatch("", 1, 9);
  EXPECT_TRUE(Visitor.runOver("int k = (4) + 9;\n"));
}

TEST(RecursiveASTVisitor, VisitsClassTemplateNonTypeParmDefaultArgument) {
  CXXBoolLiteralExprVisitor Visitor;
  Visitor.ExpectMatch("true", 2, 19);
  EXPECT_TRUE(Visitor.runOver(
    "template<bool B> class X;\n"
    "template<bool B = true> class Y;\n"
    "template<bool B> class Y {};\n"));
}

TEST(RecursiveASTVisitor, VisitsClassTemplateTypeParmDefaultArgument) {
  TypeLocVisitor Visitor;
  Visitor.ExpectMatch("class X", 2, 23);
  EXPECT_TRUE(Visitor.runOver(
    "class X;\n"
    "template<typename T = X> class Y;\n"
    "template<typename T> class Y {};\n"));
}

TEST(RecursiveASTVisitor, VisitsClassTemplateTemplateParmDefaultArgument) {
  TemplateArgumentLocTraverser Visitor;
  Visitor.ExpectMatch("X", 2, 40);
  EXPECT_TRUE(Visitor.runOver(
    "template<typename T> class X;\n"
    "template<template <typename> class T = X> class Y;\n"
    "template<template <typename> class T> class Y {};\n"));
}

// A visitor that visits implicit declarations and matches constructors.
class ImplicitCtorVisitor
    : public ExpectedLocationVisitor<ImplicitCtorVisitor> {
public:
  bool shouldVisitImplicitCode() const { return true; }

  bool VisitCXXConstructorDecl(CXXConstructorDecl* Ctor) {
    if (Ctor->isImplicit()) {  // Was not written in source code
      if (const CXXRecordDecl* Class = Ctor->getParent()) {
        Match(Class->getName(), Ctor->getLocation());
      }
    }
    return true;
  }
};

TEST(RecursiveASTVisitor, VisitsImplicitCopyConstructors) {
  ImplicitCtorVisitor Visitor;
  Visitor.ExpectMatch("Simple", 2, 8);
  // Note: Clang lazily instantiates implicit declarations, so we need
  // to use them in order to force them to appear in the AST.
  EXPECT_TRUE(Visitor.runOver(
      "struct WithCtor { WithCtor(); }; \n"
      "struct Simple { Simple(); WithCtor w; }; \n"
      "int main() { Simple s; Simple t(s); }\n"));
}

/// \brief A visitor that optionally includes implicit code and matches
/// CXXConstructExpr.
///
/// The name recorded for the match is the name of the class whose constructor
/// is invoked by the CXXConstructExpr, not the name of the class whose
/// constructor the CXXConstructExpr is contained in.
class ConstructExprVisitor
    : public ExpectedLocationVisitor<ConstructExprVisitor> {
public:
  ConstructExprVisitor() : ShouldVisitImplicitCode(false) {}

  bool shouldVisitImplicitCode() const { return ShouldVisitImplicitCode; }

  void setShouldVisitImplicitCode(bool NewValue) {
    ShouldVisitImplicitCode = NewValue;
  }

  bool VisitCXXConstructExpr(CXXConstructExpr* Expr) {
    if (const CXXConstructorDecl* Ctor = Expr->getConstructor()) {
      if (const CXXRecordDecl* Class = Ctor->getParent()) {
        Match(Class->getName(), Expr->getLocation());
      }
    }
    return true;
  }

 private:
  bool ShouldVisitImplicitCode;
};

TEST(RecursiveASTVisitor, CanVisitImplicitMemberInitializations) {
  ConstructExprVisitor Visitor;
  Visitor.setShouldVisitImplicitCode(true);
  Visitor.ExpectMatch("WithCtor", 2, 8);
  // Simple has a constructor that implicitly initializes 'w'.  Test
  // that a visitor that visits implicit code visits that initialization.
  // Note: Clang lazily instantiates implicit declarations, so we need
  // to use them in order to force them to appear in the AST.
  EXPECT_TRUE(Visitor.runOver(
      "struct WithCtor { WithCtor(); }; \n"
      "struct Simple { WithCtor w; }; \n"
      "int main() { Simple s; }\n"));
}

// The same as CanVisitImplicitMemberInitializations, but checking that the
// visits are omitted when the visitor does not include implicit code.
TEST(RecursiveASTVisitor, CanSkipImplicitMemberInitializations) {
  ConstructExprVisitor Visitor;
  Visitor.setShouldVisitImplicitCode(false);
  Visitor.DisallowMatch("WithCtor", 2, 8);
  // Simple has a constructor that implicitly initializes 'w'.  Test
  // that a visitor that skips implicit code skips that initialization.
  // Note: Clang lazily instantiates implicit declarations, so we need
  // to use them in order to force them to appear in the AST.
  EXPECT_TRUE(Visitor.runOver(
      "struct WithCtor { WithCtor(); }; \n"
      "struct Simple { WithCtor w; }; \n"
      "int main() { Simple s; }\n"));
}

TEST(RecursiveASTVisitor, VisitsExtension) {
  DeclRefExprVisitor Visitor;
  Visitor.ExpectMatch("s", 1, 24);
  EXPECT_TRUE(Visitor.runOver(
    "int s = __extension__ (s);\n"));
}

TEST(RecursiveASTVisitor, VisitsCompoundLiteralType) {
  TypeLocVisitor Visitor;
  Visitor.ExpectMatch("struct S", 1, 26);
  EXPECT_TRUE(Visitor.runOver(
      "int f() { return (struct S { int a; }){.a = 0}.a; }",
      TypeLocVisitor::Lang_C));
}

TEST(RecursiveASTVisitor, VisitsLambdaExpr) {
  LambdaExprVisitor Visitor;
  Visitor.ExpectMatch("", 1, 12);
  EXPECT_TRUE(Visitor.runOver("void f() { []{ return; }(); }",
			      LambdaExprVisitor::Lang_CXX11));
}

TEST(RecursiveASTVisitor, TraverseLambdaBodyCanBeOverridden) {
  LambdaExprVisitor Visitor;
  EXPECT_TRUE(Visitor.runOver("void f() { []{ return; }(); }",
			      LambdaExprVisitor::Lang_CXX11));
  EXPECT_TRUE(Visitor.allBodiesHaveBeenTraversed());
}

TEST(RecursiveASTVisitor, HasCaptureDefaultLoc) {
  LambdaDefaultCaptureVisitor Visitor;
  Visitor.ExpectMatch("", 1, 20);
  EXPECT_TRUE(Visitor.runOver("void f() { int a; [=]{a;}; }",
                              LambdaDefaultCaptureVisitor::Lang_CXX11));
}

// Checks for lambda classes that are not marked as implicitly-generated.
// (There should be none.)
class ClassVisitor : public ExpectedLocationVisitor<ClassVisitor> {
public:
  ClassVisitor() : SawNonImplicitLambdaClass(false) {}
  bool VisitCXXRecordDecl(CXXRecordDecl* record) {
    if (record->isLambda() && !record->isImplicit())
      SawNonImplicitLambdaClass = true;
    return true;
  }

  bool sawOnlyImplicitLambdaClasses() const {
    return !SawNonImplicitLambdaClass;
  }

private:
  bool SawNonImplicitLambdaClass;
};

TEST(RecursiveASTVisitor, LambdaClosureTypesAreImplicit) {
  ClassVisitor Visitor;
  EXPECT_TRUE(Visitor.runOver("auto lambda = []{};",
			      ClassVisitor::Lang_CXX11));
  EXPECT_TRUE(Visitor.sawOnlyImplicitLambdaClasses());
}

} // end namespace clang